1. Field of Invention
The present invention relates to a hinge, and particularly to a case hinge structure which is adapted for selectively adjusting a folding angle A of the case""s cover. Thus, the case hinge structure is mounted inside the case in order to protect the hinge structure for extending the service life span of the case and keep an aesthetic appearance of the case.
2. Description of Related Arts
Traditionally, a case 1 comprises a case body 1A and a case cover 1B pivotally connected to the case body 1A by means of a hinge 2, as shown in FIG. 1, wherein the hinge 2 comprises a pair of metal panels 3, 4 each having a pin slot affixed on exterior surfaces of the case body 1A and the case cover 1B respectively, and a pin 5 coaxially inserted into the pin slots of the two metal panels 3, 4 in such a manner that the case cover 1B is adapted for pivotally rotating so as to open up the case 1. However, such traditional hinge 2 has the following drawbacks:
(1) A user can only fold the case 1 cover 180 degrees from a closed position to an open position such that the user cannot adjust a folding angle A of the case cover 1B, which is inconvenient for the user since the user may not able to keep the balance of the case 1 when opening the case 1. In order to keep the case cover 1B in a desired folding angle A, a pivot arm 6 is affixed between the case body 1A and the case cover 1B, as shown in FIG. 2. However, the manufacturing cost of the case 1 will be increased by adding parts into the case 1.
(2) Since the hinge 2 is affixed on the exterior bottom surface of the case 1, when the user carries the case 1, the hinge 2 may accidentally or unintentionally be damaged by collusions or mutual friction of the floor. Thus, the hinge 2 may destroy the aesthetic appearance of the case 1 as well.
(3) The pin 5 must be strong enough to pivotally connect the case body 1A and the case cover 1B together. Due to the external collusion and the mutual friction of the metal panels 3, 4, the pin 5 may easy to worn out. So, when the pin 5 is broken, which is non-replaceable, the case 1 must be thrown away that is a waste of source.
(4) The metal panels 3, 4 of the hinge 2 is affixed on the case 1 by means of rivets, which will damage the surface of the case 1, destroy the beauty appearance of the case 1, and increase the manufacturing cost of the case 1.
(5) The case cover 1B is hard to tightly cover on top of the case body 1A due to the manufacturing deflection of the hinge 2. So, dust or rain may enter into the case 1 from a gap between the case body 1A and the case cover 1B.
A main object of the present invention is to provide a case hinge structure wherein the hinge structure is installed inside the case in order to protect the hinge structure, so as to extend the service life span of the case.
Another object of the present invention is to provide a case hinge structure wherein no pin or axle is needed in the pivot connection of the hinge structure, so as to prevent the pin or axle from being broken, which is the major and most easiest broken part of the conventional hinge structure.
Another object of the present invention is to provide a case hinge structure which is adapted to selectively adjust a folding angle A of its case cover, such that the case can be easily kept its balance.
Another object of the present invention is to provide a case hinge structure which is capable of tightly connecting the case cover with the case body together, so as to prevent a slit formed therebetween.
Another object of the present invention is to provide a case hinge structure which can keep an aesthetic appearance of the case since the hinge structure is inconspicuous and cannot be seen from outside.
Another object of present invention is to provide a case hinge structure wherein the case does not require to alter its original structural design so as to minimize the manufacturing cost of the case incorporating with the hinge structure.
Accordingly, in order to accomplish the above objects, the present invention provides a case hinge structure adapted for installing into a case, which comprises:
a case body having a box shape comprising a rear panel; and
a case cover comprising a rear wall wherein the hinge structure is affixed between the rear panel of the case body and the rear wall of the case cover in such a manner that the case cover is adapted for pivotally folding from a closed position to an open position, wherein in the closed position, the case cover is tightly cover on top of the case body, and in the open position, the case cover is pivotally folded up at a predetermined folding angle with respect to the case body;
the hinge structure comprising:
a lower joint, which is upwardly extended from the rear panel of the case body, comprising a supporting arm having a C-shaped cross-section defined a mounting slot therein; and
an upper joint, which is downwardly extended from the rear wall of the case cover, having a pivot arm rotatably and coaxially received in the mounting slot of the lower joint in such a manner a mutual friction is provided between the pivot arm and the supporting arm so as to adjust the folding angle of the case cover when opening the case.